After a year or two in Germany....as an American...you come to realize there's this church tax, and it's not really discussed much in German circles. So it's typically an accidental discovery, and you start to ask stupid questions.
Do all Germans pay it? No. It's an optional thing. But here's the kicker....if you opt out....you don't ever get a church wedding (which might be important in life), and you don't get a church funeral (which might be important as well). So Germans tend to think about quitting this tax on a continual basis. It's a major decision when they finally make it.
How much does the German church community make off this? On average...it's in the eight-to-ten billion Euro range ($12 billion dollars roughly).
Most churches will admit that they probably make most of their income via this, and the rest via the Sunday plate or old folks passing away and leaving them some cash.
Where does this start from? Germans don't tend to know the actual starting point, but you can go back through history and find this starting around 1919 with the Weimar government left in place after World War I.
The ballpark figure of what you pay? It generally runs around two percent of your income. The German tax guys usually tax you at the twenty percent rate....so if you clear thirty thousand Euro a year, then your tax would be six thousand Euro of tax, and then some fancy calculations fall into place where eight percent of that tax would be church income (480 Euro). So the church would get roughly 40 Euro a month ($50) and they'd cover all their bills and expenses with that income.
How many quit the church tax? Numbers aren't readily advertised. I suspect that the government and the church would prefer that the public not know that it's on the increase.
What you typically find is that a growing number of people stay on the church tax scheme through marriage, and to the point where the kids get their church confirmation deal done, and then the parents quit the church tax and enjoy keeping the cash to themselves.
This would also help to explain the growing business of private funerals and local halls in each community where a service is held with friends and family....outside of the church deal. When you do get invited to a German neighbor's funeral, and it's at a graveyard facility or a town-hall....you can figure the guy never paid his church tax. If it's at the church....the odds are that he paid through all those years into the church system.
The average German...will typically say it's a waste of money after a certain point. They hate the tax and most would prefer to do something else with their money. The churches? If you had to pick a dinosaur that is slowly passing away in life....the German church system is probably one of the top things on the extinction list.
Finally, you might be curious to think and wonder if other European countries do the same thing. Yes, most of them run the same deal. Most face the same extinction issue.
My general advice is to avoid getting into this discussion or asking loaded questions over the German church tax. It's something that Germans like or appreciate. And if they are paying it....they will generally grumble about how the money is being used.